But it’s the claim by opponents of the measure, including large manufacturers and agribusinesses, that food prices would skyrocket if the proposition passes that is riling proponents, mostly environmentalists, public health groups and farmers.

Proponents of labeling say the real problem with food prices is the longstanding monopoly control of agribusiness corporations, which hold genetically modified seed patents. Their influence on growers and food producers has artificially boosted costs, and any added cost of a label would be minor in comparison.

Whatever the effect on food prices for genetically modified and non-modified foods, drawing consumers’ attention to the distinction will provide them with a choice that could affect the economics of agriculture in California and beyond. It could give producers of organic and other non-modified crops a marketing advantage, and possibly a boost to their business.

“I think that when people have a choice, many people will opt out of the genetic engineering experiment, and that will benefit farmers who grow non-genetically-engineered varieties,” said Julie Cummins, education director at the Center for Urban Education about Sustainable Agriculture.

The No on 37 campaign, which gets most of its funding from food manufacturers and agricultural and chemical businesses such as Monsanto and DuPont, contends that the labels would force food manufacturers to buy more expensive ingredients to avoid having to put the scary-sounding warning on their products.

The anti-labeling campaign points to an economic study claiming that the change would increase annual grocery prices by $350 to $400 for the average California family.

Proponents of the measure, of course, dispute that claim.

The Yes on 37 campaign, endorsed by some food retailers and manufacturers, farmers markets and other consumer organizations, says labeling would not increase food costs for either manufacturers or consumers.

Miguel Altieri, a professor of agroecology at University of California, Berkeley, said trading of food commodities on Wall Street by corporations is to blame for high prices, not the prospect of a label on the package.

“Food prices have been increasing in the last two, three years all over the world, and more than 30 percent per year,” Altieri said. He said corporations that hold proprietary rights to genetically modified organisms control the commercial food system, and the markets.

Some San Francisco Bay Area farmers said the dominance of genetically altered crops in the food market reduces consumer choices.

“It’s conferring ownership of our food resources to a few corporate vested interests,” said Al Courchesne, owner of Frog Hollow Farm in Brentwood, who sells organic fruit at farmers markets in San Francisco and Berkeley. “Eventually that’s going to increase the cost of food for all human beings.”

But the economics of food can be complicated, agricultural economists say. Some experts in Northern California argue that prices of food have fallen because genetic modification saves farmers money.

Colin Carter, director of the Giannini Foundation of Agricultural Economics at University of California, Davis, said genetic engineering has allowed farmers to produce crops with fewer chemicals and improve yields.

“Ninety percent of soybean farmers are using this technology,” Carter said. “There must be some benefit to them.”

But ecological concerns persist. Some local farmers who eschew genetically modified crops say the proliferation of artificial genes in neighboring fields could ruin their crops. Scientists have found that in some instances modified pollen can blow in the wind and contaminate natural crops, making produce unfit to sell as organic.

Farmers markets in other cities are going the way of San Francisco’s. The Ecology Center, an environmental organization that operates farmers’ markets in Berkeley and Albany, also bans food containing genetically modified organisms.

Ben Feldman, the organization’s program manager, said the decision was largely customer-driven, but also tied to what environmentalists call the “precautionary principle.”

“Until we have good information that something is very safe,” Feldman said, “we should be cautious about using it.”

About the Author

Ambika Kandasamy is a reporter and an assistant news editor at the San Francisco Public Press, where she reports on international development, scientific research and local culture. She was awarded the Women Immigrants Fellowship by New America Media this year. Her work has appeared on KQED News, Christian Science Monitor, GreenBiz, Shareable, World Journal and other news websites. She received her master's degree in Journalism from Boston University in 2010.

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